Reverse it and put it on this card. As a warlock player, silence is my enemy, even as controllock. If you can delay turn 6 instant voidlord, then please do it. Make it so YOU cannot target this with spells or hero powers, and your opponent can. This will at least make you wait a turn, and spell-based decks don't have to let you trade by not playing minions.

Remember, voidlord isnt the problem, a 9 mana 3/18 taunt vulnerable to silence is not amazing against midrange/combo/silence decks, but a 6 mana 3/18 taunt with battlecry: discard dark pact and restore 8 health to your hero is too good. Fix Lackey and possibly Skull of the Man'ari, and warlock will be somewhat more balanced. I suggest that cube be nerfed to a 2/8, just so trading is less efficient, and your opponent has more time to look for silence.

Edit: Please let me know why my suggestion is getting downvoted, I would like to know what to change. Thank you.

I can't see how it was smart putting this card + voidlord (which is not even a legendary card), dark pact & a lifesteal spellstone in a single patch and expect some kind of balance.... Before Warlock was more about sacrificing health to draw cards to get more cards for stronger options of what cards to play & synergy but now with the spellstone + dark pact health is hardly an issue...

Only in the greediest of decks will this card be played. The only way this will ever be worth it is if you pull Voidlord or something else large enough, and that requires some janky deck building with no early game due to a lack of Voidwalker.